This invention relates to a method of tomography utilizing the nuclear magnetic resonance phenomenon and, particularly, to a method of imaging running blood vessels in the body.
A conventional typical method is described in a publication Radiology, May (1986), pp. 411-418. This method uses a sequence for varying the intensity only for blood flows, without affecting static portions, to take two scans so that the intensity varies only in a blood vessel portion, and extracts the blood vessels from the differential image. The principle of the method is that the movement causes spins in the blood vessel to vary in proportion to the velocity, which results in the variation of intensity.
The above-mentioned technique inherently needs to implement the differentiation (subtraction) as mentioned above, and needs to take at least two scans. Therefore, it not only takes a longer time for scanning, but also is incapable of visualizing fine blood vessels due to the displacement between the two scans.